DC voltage conversion circuit, DC voltage conversion method and liquid crystal display device

Abstract

The present invention provides a DC voltage conversion circuit, a DC voltage conversion method, and a liquid crystal display device. The DC voltage conversion circuit comprises a first diode, a second diode, a third diode, a fourth diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a voltage dividing unit, and a switching unit. The second terminal of the first capacitor is connected with the first voltage-transforming signal and the second terminal of the third capacitor is connected with the second voltage-transforming signal. The first and second voltage-transforming signals are both pulse signals, and the first and second voltage-transforming signals have opposite phases. Comparing the present invention and the conventional art, the present invention can quickly complete the transformation of the input voltage, to reduce the require time for completing the voltage transformation, which has strong driving capability and fast response speed.

What is claimed is: 
     
       1. A DC voltage conversion circuit, comprising a first diode, a second diode, a third diode, a fourth diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a voltage dividing unit, and a switching unit;
 an anode of the first diode being connected with an input voltage and a cathode of the first diode being electrically connected with an anode of the second diode; a cathode of the second diode being electrically connected with an anode of the third diode; a cathode of the third diode being electrically connected with an anode of the fourth diode; a cathode of the fourth diode outputting an output voltage; a first terminal of the voltage dividing unit electrically connected with the anode of the first diode, a second terminal of the voltage dividing unit being connected with a drain electrode of the switching unit; a gate electrode of the switching unit being connected with a first voltage-transforming signal, a source electrode of the switching unit being grounded, and the drain electrode of the switching unit being also connected with a second voltage-transforming signal; a first terminal of the first capacitor being electrically connected with the cathode of the first diode, a second terminal of the first capacitor being connected with the first voltage-transforming signal; a first terminal of the second capacitor being electrically connected with the cathode of the second diode and a second terminal of the second capacitor being grounded; a first terminal of the third capacitor being electrically connected with the cathode of the third diode and a second terminal of the third capacitor being electrically connects the drain electrode of the switching unit; a first terminal of the fourth capacitor being electrically connected with the cathode of the fourth diode, a second terminal of the fourth capacitor being grounded; 
 the first voltage-transforming signal being a pulse signal with alternative low-level and high-level, or the first voltage-transforming signal being a pulse signal with alternative high-level and low-level, 
 the first voltage-transforming signal and the second voltage-transforming signal having opposite phases. 
 
     
     
       2. The DC voltage conversion circuit according to  claim 1 , wherein a high level voltage of the first voltage-transforming signal is equal to the input voltage and a low level voltage of the first voltage-transforming signal is 0 volt. 
     
     
       3. The DC voltage conversion circuit according to  claim 1 , wherein the voltage dividing unit is a resistor;
 the switching unit is a N-type field effect transistor. 
 
     
     
       4. A liquid crystal display device, comprising the DC voltage conversion circuit according to  claim 1 . 
     
     
       5. A DC voltage conversion method, comprising:
 step S1, providing a DC voltage conversion circuit, comprising a first diode, a second diode, a third diode, a fourth diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a voltage dividing unit, and a switching unit; 
 an anode of the first diode being connected with an input voltage and a cathode of the first diode being electrically connected with an anode of the second diode; a cathode of the second diode being electrically connected with an anode of the third diode; a cathode of the third diode being electrically connected with an anode of the fourth diode; a cathode of the fourth diode outputting an output voltage; a first terminal of the voltage dividing unit electrically connected with the anode of the first diode, a second terminal of the voltage dividing unit being connected with a drain electrode of the switching unit; a gate electrode of the switching unit being connected with a first voltage-transforming signal, a source electrode of the switching unit being grounded, and the drain electrode of the switching unit being also connected with a second voltage-transforming signal; a first terminal of the first capacitor being electrically connected with the cathode of the first diode, a second terminal of the first capacitor being connected with the first voltage-transforming signal; a first terminal of the second capacitor being electrically connected with the cathode of the second diode and a second terminal of the second capacitor being grounded; a first terminal of the third capacitor being electrically connected with the cathode of the third diode and a second terminal of the third capacitor being electrically connects the drain electrode of the switching unit; a first terminal of the fourth capacitor being electrically connected with the cathode of the fourth diode, a second terminal of the fourth capacitor being grounded; 
 step S2, the first voltage-transforming signal being 0 volt, the second voltage-transforming signal being the input voltage, an cathode voltage of the fourth diode being twice the input voltage; 
 step S3, changing the first voltage-transforming signal to the input voltage, changing the second voltage-transforming signal to 0 volt, and keeping the cathode voltage of the fourth diode as twice the input voltage; 
 step S4, changing the first voltage-transforming signal to 0 volt, changing the second voltage-transforming signal to the input voltage, and changing the cathode voltage of the fourth diode to three times the input voltage. 
 
     
     
       6. The DC voltage conversion method according to  claim 5 , wherein the voltage dividing unit is a resistor;
 the switching unit is a N-type field effect transistor. 
 
     
     
       7. A DC voltage conversion method, comprising:
 step S1′, providing a DC voltage conversion circuit, comprising a first diode, a second diode, a third diode, a fourth diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a voltage dividing unit, and a switching unit; 
 an anode of the first diode being connected with an input voltage and a cathode of the first diode being electrically connected with an anode of the second diode; a cathode of the second diode being electrically connected with an anode of the third diode; a cathode of the third diode being electrically connected with an anode of the fourth diode; a cathode of the fourth diode outputting an output voltage; a first terminal of the voltage dividing unit electrically connected with the anode of the first diode, a second terminal of the voltage dividing unit being connected with a drain electrode of the switching unit; a gate electrode of the switching unit being connected with a first voltage-transforming signal, a source electrode of the switching unit being grounded, and the drain electrode of the switching unit being also connected with a second voltage-transforming signal; a first terminal of the first capacitor being electrically connected with the cathode of the first diode, a second terminal of the first capacitor being connected with the first voltage-transforming signal; a first terminal of the second capacitor being electrically connected with the cathode of the second diode and a second terminal of the second capacitor being grounded; a first terminal of the third capacitor being electrically connected with the cathode of the third diode and a second terminal of the third capacitor being electrically connects the drain electrode of the switching unit; a first terminal of the fourth capacitor being electrically connected with the cathode of the fourth diode, a second terminal of the fourth capacitor being grounded; 
 step S2′, the first voltage-transforming signal being the input voltage, the second voltage-transforming signal being 0 volt, an cathode voltage of the fourth diode being twice the input voltage; 
 step S3′, changing the first voltage-transforming signal to 0 volt, changing the second voltage-transforming signal to twice the input voltage, and changing the cathode voltage of the fourth diode to three times the input voltage. 
 
     
     
       8. The DC voltage conversion method according to  claim 7 , wherein the voltage dividing unit is a resistor;
 the switching unit is a N-type field effect transistor.